Preparation of stable, solid, watersoluble, surface-active compositions containing urea and a quaternary ammonium compound



Patented Jan. 29, 1952 PREPARATION OF STABLE, SOLID, WATER- SOLUBLE,

SURFACE-ACTIVE COMPOSI- TIONS CONTAINING UREA AND A QUA-. TERNARYAMMONIUM COMPOUND Edward (J. Soule and William H.

Sheltmirc,

Niagara Falls, N. assignors to Mathicson Chemical Corporation, acorporation of Virginia No Drawing. Application March 4, 1948, SerialNo. 13,084

2 Claims. 1 This invention relates to improvements in granular,water-soluble, surface-active compositions containing effectiveproportions of watersoluble, surface-active quaternary ammoniumcompounds.

A large number of water-soluble, surfaceactive quaternary ammoniumcompounds are known. In general, these compounds are substitutedammonium salts in which all four of the hydrogens of the ammoniumradical are substituted by organic radicals at least one of whichcontains a chain of eight to sixteen carbon atoms. While it is possibleto produce such watersoluble, surface-active quaternary ammoniumcompounds which are solids at ordinary atmospheric temperatures, thecost of the special raw materials required makes the cost of suchcompounds prohibitive in terms of commercial application. Further,although such compounds may be described as solids, they frequentlyexhibit an oiliness or greasiness which causes them to agglomeraterapidly when originally flaked or granulated.

For example, cocoanut oil is a low cost raw material for the productionof a particularly valuable group of such quaternary ammonium compounds,the distribution in length of the carbon chains of the constituent fattyacids being such that the quaternary ammonium compounds formed byconversion of the mixed fatty acids to amines followed by methylationand reaction with benzyl chloride are unusually effective surface-activeand bactericidal agents. However, even when substantially anhydrous,these compounds are normally either an oily liquid or a greasy solid. I

Other known water-soluble, surface-active quaternary ammonium compoundsinclude a lauryl dimethyl benzyl ammonium chloride, cetyl trimethylammonium bromide, heptadecyl trimethyl ammonium chloride, laurylpyridinium chloride, octadecyl pyridinium bromide, decyl chlorobenzyldiethyl ammonium chloride, undecyl benzyl diethyl ammonium bromide, andthe like.

These quaternary ammonium compounds are effective in dilutions of aslittle as 1 s%, 100% or even /1ono%. for example in sanitizing vesselsand utensils used in connect on with food and drink, and are commonlyused in aqueous solutions of such concentrations. For this reason, andthe further reasonthat they are conveniently prepared in aqueoussolution, these compounds are commonly manufactured and distributed asaqueous solutions containing from about to about of the quaternaryammonium compound.

In general, the ultimate consumer would prefer, for a variety ofpractical reasons, to receive such quaternary ammonium compounds as agranular solid, but for the oily or greasy characteristic previouslymentioned. Further, since these compounds depress the freezing point oftheir solutions very little, containers in which such aqueous solutionsare shipped, stored or handled must be protected against freezing toavoid losses resulting from resultant container damage. Of course, anysuch solid product must be of the same order of solubility as thequaternary ammonium compound itself if its practical value is to bemaintained.

This problem has been recognized. for some time and various expedientsfor dealing with it have been suggested. Probably the most effective ofsuch proposals has been that of fusing the quaternary ammonium compoundwith urea.

In some proportions, reasonably dry solids canbe thus prepared but afusion temperature upwards of about 110-115 C. is usually required toobtain a homogeneous product and such temperatures initiate a curiousdecomposition that continues for an indefinite period even after thefusion is solidified and cooled to ordinary atmospheric temperatures.Such decomposition not only involves substantial losses of the effectiveagent but also renders the product ob jectionable during handling and inuse.

Proposals involving the admixture of some inorganic salt with thequaternary ammonium compound, to take up any water present, have beenless than successful for the reason that the difficulties involved arenot to be solved merely by removing or binding the water present. Theproduct remains an oily or greasy product tending to agglomerate.

This invention relates particularly to improvements in granular,water-soluble, surface-active compositions containing effectiveproportions of a water-soluble, surface-active quaternary ammoniumcompound and urea.

A mixture of urea in major proportion and such quaternary ammoniumcompounds in minor but effective proportion can be fused to produce ahomogeneous melt, but the temperature required to obtain a homogeneousfusion from such simple mixtures usually exceeds 110-115 C. and suchtemperatures initiate the curio'i s decomposition previously mentioned.The decomposition products include ammon a and more odoriferous reactionproducts and the decomposition reaction,

decomposition products for a lon -period. This I decomposition is notarrested by cooling and solidifiying the fusion or melt.

We have discovered that mixtures of urea comprising not more than about80% by weight on the total of urea, about 12%-22% by weight on the ureaof such water-soluble. surface-active quaternary ammonium compounds andabout ift-6.5% by weight on the total of urea and quaternary ammoniumcompound of sodium acetate can be fused to produce a homogeneous melt attemperatures above normal atmospheric temperature but not exceedingabout 110 0., usually at about 95100 C.. and that at such temperaturesthe decomposition previously mentioned does not occur. Some negligibledecomposition may occur but it does not continue after the melt iscooled and solidified. This surprising effect enables us to produce astable, granular, water-soluble homogeneous surface-active compositioncomprising an effective proportion of the quaternary ammonium compoundby producing a fusion in this manner and then cooling the fusion andeither flaking or granulating the fusion as it cools and solidifies orgrinding the solidified melt.

The granular product of our invention com prises urea, but not more thanabout 80% by weight on the total product of urea, about 12 /;-22% byweight on the urea of a water-soluble. surface-active quaternaryammonium compound and about 4%-6.5% by weight on the total of urea andquaternary ammonium compound of sodium acetate. This product may containas much as by weight on the total of urea, quaternary ammonium compoundand sodium acetate of water. The quaternary ammonium compound may besupplied to the fusion operation. for example, as an aqueous solutioncontaining 50% by weight of the quaternary ammonium compound. The directproduct of such fusions will, within the stated limits, be stablesolids. Or, the quaternary ammonium compound may be dehydrated.partially or to substantially anhydrous condition, before being suppliedto the fusion operation. Again, the melt produced by fusing aconcentrated aqueous solution of the quaternary ammonium compound withthe urea and sodium acetate may be dehydrated after solidification. Inany dehydration of the quaternary ammonium compounds or productscontainin them, temperatures involving decomosition are to be avoided.One particularly advantageous product of our invention comprises urea,but not more than about 80%, by weight on the total product of urea,about 12%22% by weight on the urea of a water-soluble, surfaceactiveuaternary ammonium compound, about ice-6.5% by weight on the total ofurea and quaternary ammonium compound of sodium aceta te and about 8.5%-14% by weight on the total of urea, quaternary ammonium compound andsodium acetate of water.

The proportions stated are important. If the proportion of urea isincreased, higher temperatures are required to produce a clear,homogeneous melt. If the proportion of quaternary ammonium compound, orthat of water, is increased, the products do not solidifysatisfactorily, in particular the products do not flake or granulatereadily. If the proportion of sodium acetate is decreased, the fusiontemperature required tends to increase and the products do not solidifysatisfactorily, in particular the products do not flake or granulatereadily. If the proportion of sodium acetate is increased, the productsbecome hygroscopic and tend to deliquesce and to-agglomerate.

The following examples will illustrate the practice and the products ofour invention. In these examples. all parts are parts by weight.

Example I A water-soluble, surf ace-active quaternary ammonium compoundwas derived from cocoanut -oil fatty acids, by conventional processing,by

conversion of the fatty acids to the corresponding cocoa amines,methylation to form dimethyl cocoa amines and treatment with benzylchloride to produce cocoa dimethyl benzyl ammonium chloride in the formof a 50% by weight aqueous solution.

20 parts 01' this solution of the quaternary ammonium compound, 75 partsof urea and 5 parts of anhydrous sodium acetate were fused, withstirring, to a homogeneous melt at a temperature of 103 (3., fusionbeing carried out in an oil bath. This fusion was cooled, solidified andgranulated and this granular product was air dried to a total watercontent of about 1% by weight. The product had no ammoniacal odor and itremained granular and free flowing on prolonged exposure to air at F.with a relative humidity of 68%. Glasses rinsed in a solution of theproduct containing 400 parts per million of the quaternary ammoniumcompound were free of odor.

Example II 20 parts of the same solution of the quaternary ammoniumcompound, 75 parts of urea and 5 parts of anhydrous sodium acetate werefused to a clear melt at a temperature of -100 C. in a stainless steeloil jacketed pan. A stainless steel roll, cooled by internal circulationof water at 10 C., dipped into the fusion in the pan, was slowlyrevolved while the film formed on the. roll was scraped off. The film onthe roll had a, temperature of about 21 C. as it was removed from theroll and was about 0.040" thick. About 33 lbs. of the flake product wererecovered per square foot of roll surface per hour. The product wasodorless and. remained granular on prolonged exposure to air at 80 F.with a relative humidity of 68%.

Other materials may be compounded with the product of our invention. Forexample, other surface-active materials such as sodium lauryl sulfate,potassium mono-naphthalene sulfonate and alkyl aryl polyether alcohols,and alkylol amides, sodium carbonate, sodium bicarbonate, normal andacid orthophosphates, polyphosphates such as triphosphate andtetraphosphate. polymetaphosphates, pyrophosphates and borates includingborax may be included in the composition.

The products of our invention may also include, for example, 2%-5% byweight on the total of urea and quaternary ammonium compound of glacialacetic acid, concentrated sulfuric acid or syrupy phosphoric acid.

The process of our invention is, in a broader aspect, applicable to theproduction of homogeneous, solid products comprising urea and suchwater-soluble, surface-active quaternary ammonium compounds in castshapes, for example, rather than in granular form. If the product is notto be granular, the proportions of quaternary ammonium compound on theurea may be varied over wider limits than those previously stated forgranular products. For the production of such non-granular solidproducts, the

proportion of the quaternary ammonium compound may range from 3% to 35%by weight on the urea. I

We claim:

1. A method of compounding stable, solid, water-soluble, surface-activecompositions which comprises fusing together urea, in major proportionbut not more than 80% by weight on the total composition of urea, and 12%-22% by weight on the urea Of a water-soluble, surfaceactive quaternaryammonium salt in which all four hydrogens ofthe ammonium radical aresubstituted by organic radicals at least one of which contains a chainof 8 to 16 carbon atoms and 4%-6.5% by weight on the total of urea andquaternary ammonium compound of sodium acetate at a temperature abovenormal atmospheric temperature and not exceeding 110 C. and cooling andsolidifying the fusion. a

2. A method of compounding stable, solid, water-soluble, surface-activecompositions which comprises fusing together urea, in major propor- 6tion but not more than 80% by weight on the total composition of urea,and 3%-35% by weight on the urea of a water-soluble, surface-activequaternary ammonium salt in which all four hydrogens of theammonium-radical are substituted by organic radicals at least one ofwhich contains a chain of 8 to 16 carbon atoms and 4%-6.5% by weight onthe total of urea and quaternary ammonium compound of sodium acetate ata temperature above normal atmospheric temperature and not exceeding 110C. and cooling and solidifying the fusion.

' EDWARD C. SOULE.

WILLIAM H. SHELTMIRE.

REFERENCES CITED OREIGN PATENTS Country Date Great Britain Mar. 6, 1936Number

1. A METHOD OF COMPOUNDING STABLE, SOLID, WATER-SOLUBLE, SURFACE-ACTIVECOMPOSITIONS WHICH COMPRISES FUSING TOGETHER UREA IN MAJOR PROPORTIONBUT NOT MORE THAN 80% BY WEIGHT ON THE TOTAL COMPOSITION OF UREA, AND12%-22% BY WEIGHT ON THE UREA OF A WATER-SOLUBLE, SURFACEACTIVEQUATERNARY AMMONIUM SALT IN WHICH ALL FOUR HYDROGENS OF THE AMMONIUMRADICAL ARE SUBSTITUTED BY ORGANIC RADICALS AT LEAST ONE OF WHICHCONTAINS A CHAIN OF 8 TO 16 CARBON ATOMS AND 4%-6.5% BY WEIGHT ON THETOTAL OF UREA AND QUATERNARY AMMONIUM COMPOUND OF SODIUM ACETATE AT ATEMPERATURE ABOVE NORMAL ATMOSPHERIC TEMPERATURE AND NOT EXCEEDING 110*C. AND COOLING AND SOLIFYING THE FUSION.